Coupling means for coaxial electrical lines



Dec.. 2257 1953 J. R. BIRD COUPLING MEANS FOR COAXIAL EL ECTR I CAL 3L.i"

Filed may 2l, 1948 NVENTOR James R. .Bird

V/wa )L 7* ATTORNEYS Dec. 22, 1953 J. R. BIRD 2,563,753

COUPLING MEANS FOR COAXIAL ELECTRICAL LINES Filed May 2l, 1948 2Sheets-Sheet 2 55 44 E 94 48 47 4Z D //9 F19' 13 INVENTOR James R. Bird"gill/lll! l ATTORNEYS Patented Dec. 22, 1953 COUPLING MEANS FOR COAXIALELECTRICAL LINES James R. Bird, ChagrihnrFalls, Ohio Application May 21,1948, Serial No. 28,428

23V Claims.

This invention relates to electrical line coupling devices andmorelparti'cularly to means for coupling coaxial components or lines ofhigh frequency electrical circuits In high frequency electrical devicestlievarous components or parts are frequently'connected by coaxialcables or lines comprising outertubular conductors and inner conductorsinsulated from and concentrically supported with respect to the outerconductors. Considerable difficulty has been ex- 4 erienced in makingsatisfactory electrical connections between the ends of coaxial lines orcables thatk are to be joined or coupled .together and between thevariouselectrical components and the connectingcoaxial cables` or linestherefor.

The development of vthe art has provided line coupling devices in Vwhichthreaded plugs on tubular outer conductors or devices are received inthreaded collars or sockets on the ends of other components or lines andthe parts are thus secured together. vSuch arrangements are not entirelysatisfactoryA since it frequently occurs that a coaxial line having athreaded plug end must be connected to another line or electricallcomponent also having a threaded plug end.-

The present invention has for one of its principal objects the provisionofV a coupling structure for coaxial lineswhich isof universalapplication, permitting the ends of lines to -beconnectedto one anotherinterchangeably and alternatively to the ends of different coaxialelectrical components without regard to the matter of mating internaland externalthreads or the like.

Another difiicultyencountered in the coupling of coaxial linesandcomponents is axial misalignment of outer tubular conductors. Suchmisalignment, resulting `in radial shoulders at the joints, is apt to.give rise to objectionable reflections during the yfunctioning of thecircuit. The invention thereforecontemplates as another of its objectsthe provision of coupling means which insures axialalignmentcof. theadjacent ends of the outer conductors of coaxial lines at thecoupling.As a preferential arrangementv it is sought to provide pilot means forguiding the ends vof tubular conductors of cable end ttings intopredetermined coaxial: alignment as Ithey lare drawn together intoabuttingrelation in `a coupling structure;

Another acute problem lencountered in the construction ofhigh frequencyelectrical devices is the connecting .of coaxialcomponentsor lineshavingconductors .ofrdiierent diameters.' To avoid .reflections andother objectionable phenomena,` certain diameter ratios are maintainedbetween the :inner'and outer conductors of a coaxial line, the ratiovarying Ywith the dielectric constant of' the insulating materialseparating .the conductors. While it may appear that conductordiametersvand dielectric material can change abruptly so long as basicltheoretical ratios and relations areadhered to, superior results areobtained in high frequency coaxial circuits in which changes inconductor diameters are eifected gradually. Therefore a further objectof the invention is concerned with the provision of coupling means forconnecting one coaxial line 0r cable to another such line or cable or toa coaxial electrical component having conductors of diierent diameters.Moreparticularly, this aspect ofthe invention contemplates the provisionof a tapered coaxial line coupling in which the transition from onediameter is effected gradually, preferably over tapered conductors thatare several times longer than their maximum diameters.'

A still further object isto provide a coaxial line coupling device whichincorporates improvements in the means vfor electrically connecting theinner conductors. More specifically, this aspect of the invention seeksto provide inner conductor connecting meanslrwhich effect electricalconnections ofjthe inner conductors at a substantially uniform vorconstant diameter across the connection. Asa further renement of thisphaseof'the invention the inner connector provides for limited axialmovement of the inner conductors toward and away from one another `whilemaintaining the electrical connection therebetween. Such an arrangementpermits the coupling together oi' coaxial lines or components withtheouter conductors thereof in rigid or nonyieldingabutment, vslightirregularities and tolerances in length beinglcompensated for by thelongitudinal adjustment provided in the connector structure joiningtheends of the inner conductors.

vThe above andotherobjects and vadvantages ofthe invention pertaining todetails of construction andarrangements of parts which will becomeapparent as the following detailed description proceeds are embodied incoupling structures whichare simple and inexpensive to manufacture andwhich incorporate' a minimum number of parts. The description isfmadewith reference to the accompanyingcdrawings forming a part of thespecification. Like parts throughout the several views are in dicatedbythe same letters and numeralsofreference.V

patent Serial No. 777,516, led October 2,

drical end portions In the drawings:

Figure 1 is a longitudinal sectional view, with parts broken away andremoved, showing a coupling for connecting a high frequency coaxialcomponent to a coaxial line of different or smaller diameter;

Fig. 2 is a transverse sectional view, with parts broken away andremoved, taken substantially on the line indicated at 2-2 of Fig. l;

Fig. 3 is a transverse sectional view with parts removed, takensubstantially on the line indicated at 3-3 of Fig. l;

Fig. 4 is an expanded fragmentary elevational detail, partly in sectionand with parts removed, showing the meeting ends of the inner conductorsin separated relation and on an enlarged scale with respect to Fig. 1;

Fig. 5 is an elevational detail partly in section and similar to Fig. 4,showing the meeting ends of the inner conductors in assembled relation;

Fig. 6 is a transverse sectional detail taken substantially on the lineindicated at -c of Fig. 5;

Fig. '7 is an elevational view partly in longitudinal section and withparts broken away and removed showing the meeting ends of a universalcoupling structure of the present invention, the conductors being ofuniform diameter;

Fig. `8 is a detail showing an end View of one of the inner conductorsof the preceding ligure, this view being taken along the line indicatedat ti-'e of Fig. 7 and enlarged with respect to that View;

Fig. 9 is an elevational View partly in section, showing the connectorelement or plug for the inner conductors of Fig. 7 on an enlarged scalewith respect to that figure;

Fig. 10 is an elevational view partly in section and with parts brokenaway and removed, vshowing a universal coupling structure of modifiedform employing a splice insert;

Fig. 1l is a fragmentary sectional detail taken longitudinally throughanother universal coupling structure which employs a modined form ofsplice insert;

Fig. 12 is a perspective view of a plug type connector element forjoining the ends of the central conductors of a coaxial line; and

Fig. 13 is a fragmentary sectional detail tairen longitudinally througha coupling structure such as that of Fig. 7 showing a modificationemploying the connector plug of Fig. 12.

Coupling structures such as shown in Figs. l through 6 are useful inconnecting high frequency coaxial components to lines or othercomponents having different diameters. For example, it might connect thehigh frequency electrical device or resistor of my copending applicationfor i947, now Patent No. 2,556,642, issued June l2, 1951, to a coaxialline having an outer conductor of relatively small diameter. In theillustrated structure a transition device A is connected at its smalldiameter end to the connector B of a coaxial line and at its other orlarge diameter end to resistor -device C which is the high frequencyelectrical device disclosed in the copending application referred toabove.

The transition member or device A comprises an outer tubular conductorof metal such as brass,

of substantially circular cross to end, and formed with cylinl and 2 anda tapered or frustoconical central portion 3. The major por- .tion ofthe length of the transition member is embodied in the tapered portion3, the length of which is several times its maximum diameter,

copper or bronze, section from end being at least about twice as long asits maximum internal diameter and preferably about three or more timesas long as its maximum internal diameter. The tapered portion 3 is alsolonger than either of the cylindrical portions l and 2 and may beintegral with such portions or formed separately and joined thereto incoaxial relation as by telescopic joints, one of which is indicated atll. Such joints are securedA by brazing or soldering.

AThe coaxial line or cable (not shown in Fig. l) is conventional andterminates in a conventional end connector which includes outerconductor 5 and inner conductor 5 separated by a tube i of suitabledielectric material. A knurled collar 8 is formed at one end with aradial flange received with a running rit in a circumferential groove inthe outer conductor 5 of the cable end connector. The other end of thecollar is internally threaded and received over the externally threadedsmall diameter end portion i of the transition member as indicated at d.

The large diameter end portion 2 of the transition device A isexternally threaded and connected by universal coupling assembly D toend connector or iitting E of a coaxial line or oomponent. The connectorE comprises a tubular outer conductor element IS having at one end asquare flange IE secured by cap screws I2 to a matching flange i3 of ametal member 2l attached as by solder to the coaxial electricalcomponent or structure C. rlChe member 21 corresponds to the connector2l described in the above referred to copending application and themetal cone or outer member id corresponds to the connector it disclosedin the same application.

rihe inner conductor 6 of the coaxial line connector B terminates in areduced diameter portion which is received within a longitudinal splitsleeve portion E5 of a contact element 2Q on the small end of taperedinner conductor il of the transition device. The tapered inner conductoril has an integral cylindrical portion IB at its small diameter enddisposed coaxially within the cylindrical end portion l of thetransition outer conductor. The Contact element 20 is of the samediameter as the conductor portion i8 and is telescoped over and solderedto a reduced diameter end of the conductor portion i8.

Within the large diameter cylindrical portion 2 of the transition outerconductor the inner conductor il is formed with an integral cylindricalend 2i electrically connected to a cylindrical inner contact element 22disposed coaxially in the tubular outer conductor element lll. Theelement 22 is received as by telescopic fit 2d and soldered on the smalldiameter end of tapered inner connector 23 of the electrical component Cterminating the coaxial line.

The inner conductor El or at least the cylindrical end 2! thereof isformed of resilient spring-like conductive material such asberyllium-copper or bronze and the end 2! is axially drilled andlongitudinally split along diametric intersecting planes, forming aplurality of parallel spring-like (Figs. 4 6). Conical or taperedsurfaces 25 on the ends of the tines are slidably received'within atapered socket 25 on the end of the contact element 22. The tines on theend 2i of the inner conductor are initially sprung apart as shown inFig. 4 so that, as the parts are drawn together in assembly, the taperedsurfaces 25 on the ends of the tines contact and bear against thetapered surface 2g of the receiving socket and are radially compressed,

thereby effecting positive electrical connection between the partswhich, by reason ofthe resiliency of thetines, is maintained'for slightaxial shifting or movement of. the conductors.

Preferably the slopes of the tapered surfaces 25 and are such that inassembled'relation (Fig. 5) the tips or small endsof the tines on theconductor portion 2l are separated 4from the surrounding socket walls 26byan annular space 30. The angle of the conicalsocket 26 is less thanthe angle or slope of the conical or tapered tine ends 25. Electricalcontact between the tines of the conductor end 2l and the element 22 isthus established and maintained substantially at thin, knife-like tipend 3l of the contact element. By this arrangement electrical connectionbetween the component parts of the inner conductor iseifectedsubstantiall'y. at the maximum diameter of the conductor, thusobtaining improved transmission characteristics in' high frequencyelectrical applications.

Supporting the inner conductor l1 within the tubular outer conductor ofthe transition member A is an insulating body 33 of solid dielectricmaterial such as polyethylene or other thermoplastic coinposition. Thisinsulating dielectric is continuous substantially from end to end Vofthe transition device A including the cylindrical end portions l and 2.The insulating dielectric 38 has a coenicient ci thermall expansiondifferent from that of the bronze, copper, or brass, cf which theconductors 3 and I1 are made and provision is made for differentialexpansion and contraction in the form of elongated axially extendingslots 3e cut in the tapered portion 3 of the outer conductor. Theseslots permit radial expansion and contraction of the insulating di-Aelectric to and minimize any tendency of the dielectric to shift orexpand axially under temperature changes. Thus axial shifting of theinner conductor is eliminated.

Another insulating body 33 of solid dielectric material fills theannular space between the tubular conductor element In and the inner`element 22 and supports the latter in coaxial relation to the former.The insulating dielectric 33 being subject to the heat of the oil iilledelectrical component or resistor device C is of heat resistantcomposition such as pclytetrafluoroethylene and serves as a liquidsealing plug to retain the oil or other liquid dielectric within theresistor device. Since the dielectric plug 33 has a dielectric constantwhich diners from and is lower than that of the insuiating body 38 inthetransition device the internal diameter ofthe successive outer ortubular conductors may diier as shown. If, however, the same insulatingma# terial, or insulating materials having the saine di electricconstants, are used for the tubular plugs or bodies 33 and 38 theinternal diameters of the cylindrical end portion 2 of the transitiondevice A and conductive surface 34' of the element iii are made equal orsubstantially so, .to satisfy the fundamental principles or formulasgoverning the design of coaxial electrical lines.

Circumferentially extending flanges 35 and 35 of relatively shallowradial depth are provided at the ends of the conductive surface 34 onthe inside of the outer conductor I3 toengage the ends of the dielectricplug 33* so as to locate the latter and resist axial shifting thereof.The flange Se is formed on one end of the conductor element IQ, thedielectric plug 33 being initially inserted through the opposite end ofthe conductor element inassembly. The-flange .35 is formed internally onthe member 21 at the small diameter end 1 of the' tapered or conicalsurface 28'ther`eof. To prevent leakage'of'oil or other liquiddielectric fromthe'" chamber in the resistor device C, aresilient'dforrnable O ring 49' is interposed between the flanges HandI3, a suitable annularl` groove` being formed` in the flange IltoreceivetheO ring. The flange Il is located inwardly from the end'ofthe conductor element l0 providing an vaxial extension 4l on the latterwhich projectsk beyond the meeting plane of the 'flanges 1 I and I3 andis received'slidingly within a mating socket formed in the connectormember 21. Thusthe'conductor element I0 and thefl'angcd'inember 21 arepiloted'together during assembly to -provide positive'concentricity andestablish -the desired' electricalY characteristics;

In' a coaxial line structure involving a transition' from'cylindricalconductors' to tapered or conical conductors,4 it 'has been foundadvantageous to arrange vparts so that the plane of the circle ofintersection' between the cylindrical and conical outer conductors isonset axially with respect to the plane of the lcorresponding junctionor circle of 'intersectionof the inner conductors.` An applicationoflsu'chan arrangement is illustrated in Fig. l inthe transition betweenthe cylindrical conductors 'of the connector E and the conical'conductors of theco'axial component or device C. The inner""conductivesurface of the tubular element |70 and'the'inner conical face 28 of themember' 21 intersect in a plane indi cated at 29. This plane containsthe end face of the 'soliddielectric orinsulating plug 33 and is themeeting plane ofthe liquid and solid dielectrics.

The plane 'of interse'ction'between the surface of the conicalinner'conducto'r 23 and the cyiindrical conductive'faceof'theconductor22 is indicate'd at 32, coinciding" with the shoulder against which isabutted the end of tubular portion 24 of the cylindrical conductor. Theintersecting Vplane 32'of theinne'r conductors is offset axially'withrespect'to theintersecting plane 29 of the outer conductors in thedirection of the large ends of the Vconical conductors. The amount ofsuch onset varies with the cone angle or taper of lthe conical'conductors and with the diameters of the cylindrical conductors. It hasbeen found that a satisfactory approximation is realized in laying out'the design of the line by describing a circular arc 31'representing aspherical surface with center 51 thereof substantially at the apex ofthe cone derlnedby the elements of one of the tapered conductive'surfaces and with the ends of the arc crossing the 'intersection betweenthe cylindrical conductive surface 34 and the conical conductive surface28. Thus the spherical surface of 'the arc 31 contains the circle ofintersection between the tapered and cylindrical conductive' surfaces.The offset between the plane 29 andthe'plane 32 is such that thespherical surfa'cegerirated'by a'radius from' the common 'center 551Vcontains the circles of intersection between the" cylindrical andconical portions of 'both the inner and the outer conductive surfaces'.

The center point 51,'showr'i`as the center of the cone of the oute'rtapered surface,.also 'coincides with the apex of the'cone defined bythe surface elements of the inner `conical conductor 23. Thus, in'designing tapered transition devices for connecting coaxial lines orcomponents of different diameters, the tapers or 'slopes of the innerand outer conductive surfaces and also the axial offsets of the severalplanes of intersection between the conical and cylindrical surfaces arereadily determined by employing this point intersection method.

For example, in laying out the transition device of Fig. 1 therelationship between the conicalY inner surface of the tapered portion 3of the outer conductor and the conical surface of the inner conductor Ilis established by arranging these surfaces so that extensions of theirelements intersect at a common point. Such point is the apex of the coneof the inner conductor and alsoy the apex of the cone of the outerconductor. This point of intersection, or common apex, is the centerfrom which are struck the arcs of the spherical surfaces which containthe circles of intersection between the tapered surface of the innerconductor Il and its cylindrical ends I3 and 2|. These arcs alsointersect the outer conductor of the transition device at theintersections between the conical conductive surface of the taperedportion 3 and the conductive surfaces of the cylindrical end portions iand 2. In this connection it is to be noted that the single pointintersection or common cone apex provides the center for the are orspherical surface establishing the axial osets, not only as between thetapered'and cylindrical surfaces at the small diameter end.` of thetransition device, but also as between the tapered and cylindricalsurfaces at the relatively large diameter end of the device.

The universal coupling structure or assembly D which draws the4transition device A and the resistor device C axially together into endto end abutting relation includes a pair of sleeves 42 and 43 which areinterlocked against axial separation but are relatively rotatable forturning about a common axis. For example, the sleeve 43 may be formed atone end with a circumferentially extending outwardly directed radialflange 44 which is received behind and is overlapped by acircumferentially extending inwardly directed radial flange 45 on oneend of the sleeve 42, the iianges and sleeves being sized to providerunning ts.

The cylindrical end portion 2 of the transition member A and theabutting end portion, also cylindrical, of the conductor element I areformed with external threads that are identical and of the samediameter. The coupling sleeve 43 is formed with matching internalthreads so as to be receivable on either the transition member A or theconductor element I6. An outer portion 5l .or the sleeve is unthreadedand serves as a guide in screwing the sleeve onto the tubular member ofthe coaxial line or component being assembled therewith. In thearrangement illustrated the threaded connection of the coupling sleeveon the conductor I0 is indicated at 46. An internally threaded collar 41is received as by a press t within the coupling sleeve 42 and serves asa stop for engagement with the flanged end of the sleeve 43 to hold thecoupling sleeves in assembled relation. A thin axial flange 4B formed onthe end of the coupling sleeve 42 remote from the flange 45 is rolled orpressed radially inwardly against a tapered or conical end face 49 onthe collar 4l to retain the latter on the sleeve. Suitable means such assoldering or bracing may also be used to supplement the press t betweenthe parts to resist relative movement of the coupling sleeve 42 on thecollar 41.

The internal threads on lthe collar 4l are identical to the threadsformed on the interior of the coupling sleeve 43 and are received on thethreaded end of the transition member A, the threaded connection betweenthe parts being indicated at 56. An outer portion of the internal faceof the collar 4l is without threads and serves to guide the parts intocorrect alignment during assembly. rlhus while the coupling sleeve 43 isshown screwed on to the conductor element lli and the threaded collar ofthe coupling sleeve 42 is shown threaded on to the transition member Athe parts are so designed and constructed that they may be reversed withthe sleeve 43 on the transition device and the sleeve 42 on the l5conductor element i4 of the resistor device terminal. Furthermore, theprovision of the externally threaded end on the terminal element I9permits 4the resistor device (or electrical component) C to be connectedto conventional coaxial lines of the proper size having attachingcollars corresponding to the collar 8 described in connection with thecoaxial line B. The external threads o-n the cylindrical end portion 2of the transition device enable the latter to be connected to coaxialdevices, components, or lines other than the resistor shown, eitherdirectly or by using the universal coupling D of the present invention.

in the coupling of coaxial lines and devices it is vital to maintainconcentricity and also to maintain positive electrical connectionbetween the abutted outer or tubular conductors around substantially theentire circumferential extent of the latter. lt is especially importantthat the electrical connection between the outer or tubular conductorsbe established at the inner diameter thereof so as to eliminate diameterchanges along the length of the transmission line. Otherwise,objectionable wave reflections are apt to occur in the transmission ofhigh frequency current and perfect transmission cannot be obtained. lnthe universal coupling structure of the present invention, accuratealignment of the abutted ends of the outer or tubular conductors isobtained by a circular pilot ring 52 carried by one of the couplingsleeves, the sleeve 43 in the embodiment illustrated. rllhis pilot maytake the form of an integral circumferentially extending inwardlydirected radial flange of relatively short axial length which spans thegap between the ends of the outer conductors to serve as a guide as theinner conductors 2i and 22 are initially engaged and drawn together bythe screw action of the coup-ling sleeves.

At the extreme ends of the externally threaded portions of thetransition device and the conductor element le are thin shell-likecylindrical flanges `i3 which are drawn into circumferential abutmentwith one another as the line structure is assembled. The shell flanges53 have inner surfaces which extend as continuations of the respectiveconductive inner `surfaces of the tubular conductors on which they areformed. By reason of 4the thin section of the shell flanges 53 theyeffect positive electrical contact under the contractive pressureapplied to the joint by the coupling sleeves 42 and 43, the electricalcontact being established around substantially the entirecircumferential extent of the joint.

In assembling the universal coupling structure of the present inventionthe sleeve 43 is initially screwed onto one of the tubular outerc-onductors until the pilot flange or guide 52 is received on the shellflange 53 and is disposed against a shallow radial limiting shoulder 54of the cony manually vr,or thesleeve 42 is threaded `onto the secondtubufductor. Thereafter Ythe end. ttinsfof thefother e orf electricalcomponent :beine Aconnected is brought into registry-and the col1ar41lar conductor. As the tinesof the cylindrical .eendll of one of theinnerconductors are received v,within the tapered socket 26 of the votherinner conducto-r, the shell 1'lange53 of the seco-nd outer conductor isreceivedwithinfthe :pilot flange "52 and is guided thereby .intoaccurate alignment with Yand abutment against the shell viiange 53 .ofthe rst outerconductor. To facilitate assensbly the leading edge cornersof the inside vfaceof ythepgilot ilange or guide 52 are 'beveled orrelieved Yto pro-vide the charners shown.

In Fig. 7 -is illustrated .an application of the .principles of thepresent invention to la universal lcoupling structure for .connectingthe ends of coaxial lines or cables. The couplingsleeve assernlolyv Dlis of .substantially thesarne construction as that described in thepreceding figures. Afset screw. 55 is shown as an alternate. means Y for.locking the threadedcollar 41 against relative rotation or movement inthe sleeveAZ.

A pair of substantially identical rigid tubular outer conductorsr(corresponding parts of coaxial component, line or Acable ,connectors E.to be connected) ,are 4formedon their endswith identical externalthreads 58 which receive alternatively the internallythreaded collar 41.of the Vsleeve 42 and the internally threaded sleeve 43.

VAt their extreme meeting lends the conductors 1156er@ formed withthinsh'ell-like axially directed fiianges' Sil ycorrespondingi to `the,flanges ,53 .de-

scribed in ,connection .with Fig. 1. AThe inner cylindrical surfacesofthe flanges 60 are the same diameter as and extend as continuations ofthe inside; faces of the tubular conductors. The shell 'flarlees arebrought. into abutment with one another under relatively high localizedpressure and a relatively smooth substantially unbroken conductivesurface is provided across the joint for the transmission of electricalcurrent.

In assembling the ends oftcoaxial components, lines or cables thecoupling sleeve `i3 yis rst screwed onto the rigid outer tubularconductor of one or the cable end connectors E until the pilot flange orring 52 of the -coupling'sleeve Yis abutted against circumferentialshoulder El of such conductor. This nshoulder corresponds to theshoulders 5 previously describedand is present on both or the tubularouter conductors A5t -so that the coupling sleeves Vl2 and l43 areVrever- -sible on the conductors. yAfter the sleeve `43 is assembled onthe outer conductor of one of the cableend'connectors-with the shellflange ..160 of the latter embracedby the guide ring 52, the other cableend connector is brought into registry andthe threaded collar 41' ofthecoupling sleeve 42 is screwed into position. This action .draws theshell i'ianges into..abutment, piloted by .the guide ringgor flange 5'2.

'Theinner conductors. ofthe coaxial lines connected to the cableconnectors E terminate in vfilmer conductorelements whichgare in theform of round or cylindrical metalorods vor :bars concentricallysupported wit-hin the cuter vconductors `by annular bodies of solidinsulating or dielectric material E3. The meeting or confront- -ing-ends of the inner `conductors 6,2 are axially drilled or bored toformtubulartips-Which are yslit longitudinally. at el (Fig-5-8) forminga Vnurn- --ber offaxially extending resilient tines 5,5. The .extremefende of :the tines E5 ,are internally :benelcd 4providinginside.gtapered.or c onic faces 66. A plug type connector element 6B(Fig. 9)

vblies D.

is Vreceived between-"the vends l.of-.the :inner vconductor elements to:effect an electricalfconnection therebetween. The outerormaximumdiameter ofthe bulbousor fbiconic. central portion ofv theconnector 68 is substantiallyequal to thatffof the inner conductors-.6Iand the yends -ofv theetines S5 are tapered out .to thin .wedge shapedor knifelike edgeswhich ride up-conical facesf'l of the central portionof thefconnectorelement 4during assembly of the.coaxial-lines,-therebyneffecting electrical connection between `the.parts substantially at thermaximum diameterzof the ,connector element.The conductor `tines .65.are sprung inward .slightly tbefore@assemblyso.as individually to lbear strong-lygaeainst the `conical facesv 6.1.4 ofthe. connectorx elementeand effect .a positiveelecytricalconnectiontherewith which. is. substantially continuous `:aboutthefentire. circumferentialex- Ytent of the connectonplug.

The connector plug or element, shown enlarged in Fig. .9, includesazcentral-portionsubstantially .bconical .-in shape,.having .arelatively' longxaxis approximately coincident .With'the Aaxes vof Vthevcoaxialv line end .connectors .being joined .in the couplingstructure.Substantially.cylindrical extension ,portions .1 0 .on the .ends lofvthe connector .A elementare received within .the bores inthe ends .ofthe inner conductors 6.2 and are surrounded .by the tines thereof. Priorto assemblyof'the coaxial lines, .oneof the extensions `'HJ of 4theccnnectorelement 68 .is .inserted Within the socket or vbore .otono .oflthe, central'conductors arxd'the resilient grip of the tines retainstheconnector element .during assembly. Asp'the coaxial lines are. .drawntogetherand the'tinesiGSfi-ide up the conical or tapered faces'llofthe'connectorele ment the ex tensionslllr are released4 by the tinesand thevconnector .elementgis then centered -a-nd .held solely by'the`frictiona'lgripcf the tipr'or thin .wedge-like end edges oftheresilient tines 65 which center the plug between the `conductors andpermit limitedaxial shifting of the -conduetors without breaking orinterrupting the-electrical connection. Thediameter of the biconicalconnector plug is-substantia'lly equal to the -diarneter of the innervconductors t2 so that-theplug acts as alimiting'pilotin assembly tor'distend the'sprung int-inesf' tothe normal'dia-meter of theconductors.

The several elements of theca-ble end connectors YE of Fig. '7 terminate-in -a commonHplane which -isthe plane -of abutment of thecouplingstructure. That is,'the endiace of each. of the insulating "dielectricAbodies 163 :is .substantially flush with Athe end r=e" ige :of fthecorresponding shell ilange-BU and with the thin, 4lzniie#like/:edges ofthe innerconductoritinesilSS. Accordinglyra relatively ruggedcable endstructure or connector is provided Which resists; deformationaand injuryin use though repeatedly*.connectedand=.discon nected insmakingfvariousfhookeups of.- apparatus :III the coupling assembly A'the space :between.the inner and outer conductorsissealed off bythe dielectrics 63 :whichare-abutted against. .onetanother, excluding dust, dirt, andother.foreign materiaL'and byvthefmeeting edges-ofthe thin shell flanges-60which :are heldtogether .under relatively f high unit pressure.

In Fig. ,10 is illustrated a luniversal coupling fstructuren which theend` connectors -E of .coaxial electrical linesfare joined`byasplicelconnector F, vthe latter rbeing, retained .between .the endconnectors E byv one of @the coupling ,assemvIn ythis embodiment of .theVinvention the threaded sleeves 43, without pilot extensions,

are threaded onto opposite ends 4of externally threaded metal tube 12 ofthe splice F. This tube has an internal cylindrical face 13 of the sameV outer tube conductors 56 of the connectors E. As l the parts are drawntogether by the threaded connections the pilot rings 52 of the sleeves43 receive the shell flanges on the ends of the tubular conductors 56and guide them into abutting engagement with the mating axial shellanges 14 of the splice tube 12.

VA tubular inner conductor 16, disposed in the center of the connectortube 12 in coaxial relation thereto, is of substantially the same axiallength as the outer splice tube. This inner conductor is formed ofresilient spring metal hav ing good electrical conductivity, such, forexample, as beryllium copper, and is supported by a surrounding body ofinsulating dielectric material 11 such as polyethylene orpolytetrafluoroethylene, as used for the insulating dielectrics 63.During assembly the inner tube 16 receives in its ends tapered orconical ends 18 on the inner conductors 62 of the cable end connectorsE.

To establish electrical connection between the conductor element 16 andthe inner conductors at or adjacent their maximum diameter, the innerface of the connector 16 at its ends is tapered to form conic sockets,indicated at 69. The angle or slope of each of the internal faces 69 isless than that of the mating external conical faces 18 of the innerconductors so that electrical connection is made between the parts atthe maximum diameter of the tubular connector 16. The chamfering at theends of the tubular connector provides thin knife edges, the extremetips of which make electrical contact with the inner conductors 19around substantially the entire circumferential extent of the latter. Anumber of axial slits 8! are formed in circumferentially spaced relationabout the tubular inner conductor 19 and open alternately through theopposite ends of the latter, providing for expansion and contraction ofthe connector during assembly and disassembly. The tubular connector 16is initially slightly collapsed or sprung 'together so that the taperedsocket ends make substantially circular line contact with the taperedcones 13 of the inner conductors 62 in the initial stages of assemblyand ride up the conical contactl surfaces as the threaded outer collars41 draw the parts rmly together in the final stages of assembly. In theassembled coupling structure the diameter of the inner conductor remainssubstantially constant across the splice, there being no objectionablediameter changes in the electrical connections between the spliceconnector 16 and the inner conductors 62.

The construction of the end. connectors E for attachment to coaxialcables is illustrated in Figs. '7 and 10. 'Ihe outer tubular conductors56 are similar in design to the conductor element I previously describedin connection with Figs. 1 and 2, the internal iiange 36 for retainingthe dielectric plug being omitted. Conventional coaxial lines or cableson which the end connectors E are assembled each comprise an outerconductive shield 82 formed of diagonally woven or braided conductivemetal wires or tapes, an inner conductor 83 in the form of a copper rodor wire, a tubular insulating body 84 which may be of the same materialas that used for the insulating dielectrics 63 and 11 of the couplingsand connectors, and an outer protective tubular jacket 85 of toughabrasion resistant insulating material such as a suitable vinylcompound.

An end portion of the jacket 85 is stripped. away and end 81 of thebraided shield 82 is expanded to expose the insulation 84, which is cutaway from the end of the inner conductor 83. The inner conductor 62 ofthe end connector E is withdrawn from its supporting dielectric 63 an-telescoped over the exposed end of the inner conductor 83 of thecoaxial cable. The conductor 62 is formed with an axial bore 68 thatslidingly receives the cable conductor and the parts are securedtogether as by solder. The conductor 62 is then inserted into thecentral bore in the supporting dielectric 63 and the latter is forcedsnugly against the insulating dielectric 96 of the cable. In thisoperation the expanded end 91 of the woven shield 82 is guided overaxial extension 89 of the tubular conductor 56. The woven shield isclamped between the conductor extension 89 and a radial shoulder of aflange 99 formed on the inside of a collar 9| previously placed over thecoaxial cable.

The collar is formed with a circumferentially extending square shapedradial flange 92 which matches a corresponding ange 93 on the tubularconductor 56. The flanges 92 and 93 may correspond in shape to theflanges I3 and l respectively, previously described in connection withthe device illustrated in Figs. l and 2. Cap screws, one of which isindicated at 99, extend through apertures in the flanges 92 and arethreaded into aligned openings in the flanges 93 to hold the partstogether. A seal is provided by a rubber O ring 95 received in anannular channel 96 in the end face of the flange 93. Clearance 91between the iianges 92 and 93 assures positive gripping of the woven orbraided shield or outer conductor 82 of the coaxial cable between thetubular extension 89 of the end tting .conductor 56 and the shoulder ofthe iiange 99 of the connector collar 9i. The collar 9i is splitlongitudinally as indicated at 98 so as to be contracted by an embracingdevice of the hose clamp type indicated at 99. For holding the coaxialcable within the connector collar the latter may be of any desiredlength, the design shown in the drawings being relatively short. Longercollars may employ more than one of the clamps 99 thereby obtaining astronger grip on the sheath 85 of the coaxial cable.

In Fig. 11 is illustrated a modied coupling of the universal type inwhich the tubular outer conductors 56 of the connectors E are heldtogether by a coupling assembly D like that previously described, theinternally threaded sleeve :i3 being relatively long so as toaccommodate a relatively short splice insert G between the pilot flange52 of the sleeve and the shell iiange 69 of the outer conductor 56.

splice tube |00 is provided with locating means in trionfo-'tmorasirouuriisioily. mnoiodioiogrsl .flange |03 Whichroverlapstheshellilange SQf oneof the cndu'ctorsvtie'ange L03 lining shorter.than 'the shell angef. of the conductor 'so .that `the end [of 'theflatter is forced' .snugly againstthecircular radial yshoulder ontheendirovf the shell I ilf to effect a potyefelectrialfconvn ection.`between the parts which extends around .substantially the entirevcircumferential vextent of the`conduc`tor at the diametei- Qfftheinnerfaces.

= The other .end of thesplice tube Iisfforxned ,oi its iria-o1'folio-noto? `liiflfi ari-axially @gooi-od circularlange lll which ,corrpenas to the1 shell gansos .651 of tho iublor' diistors "Tho sans@ -nuisreg ed witninthe piit. aange .5 2 v 'of'lthe couplingsY eveud, theYpilot ge'eing drawn snuglyagainst a circiimferent 1` shoulder |05 ofthe .splice tube I B so that the lattrnis .retained firmly botwogniho-Ploilongo and ilo elia' or the wenn jovaducto' 15a pms' which, thecoupling sleeve is threaded. .'Ilhe shell ange |54 of the splice tube'is'of less axial length't an the ,pilot `ilange 52 of the threaded',cu'pling sleeve so that thelatter alszoreceives andfguides ,the shellilanger of the',otherconnectortube as, the latter being heifi in piace,bythe' threaded collar d? of the coupling assembly.

,The inner' conductorsjl of the. cable .connectors ofthe embodiment ofFig. `11 arasnnilafto those` described infconnection.Withglig l0, `buthavelongitndinal slQts Yl'll'l .j 1jenir ig throughV their ends, formingtines H16 k which corn-spend tothe tines 3l of the V innenfcon'ducters,shawn in Figs. l through .6. i Tapered'orleonic rtips |68 `,cyr'ntheconductor .tines |05 are'rec'eived u iithirrthe.internally coned .ends.of a vtubular v'metal fsplice element .|133v .coaxiall'y `s uppcrtedwithin'the ,splice tube vLilli by wineans" of 'an annular bdy ofinsulating dielectric I D siinilartd Vthe. ii, uvlating body 'Hdescribedin connectinui'thig. `10. As theinnerlconductors Glare dra:Ltogethei" inaSfSfmbling -Vthe coupling', the tines |116 of. the .tubem9,. previously. distende@ or sprung apartgare 'dravvn together .by .the,action si the' tapered. tips me ,sliding withinthe .gg ical .endsocketsofthe splice elernentpr tnbetiiil.

' Each lof theconductorftips |918 hasagreiater angle of taper than vthereceivingsoclgettherefor in thetube IBS softhat electrical ce t oeiectfed ,between the VAicartsY .at .the engine tips or knife e"ofthesplice tub e atfth e.-n iax m um dianieteiyof the latter.Theresiliency .of the -tines IE6 rnaintains vpositive V)el ectricalvconnection between the parts l fqr Vslight a xia tlv orlong itudinalshifting `of the inner conductors. A splice insert having .a 4tubularinner en ndnctor will longitudinal slots opening through one end only isemployed to join vx12-able connectors one ofwhih hasv ,an innerconductor like that .ofiFig l0 the other of which has aninnencnductor vlilgze that of'Fig. 11.

igs. l2 and 13 illustrate aconipressiblehiconic plug l l5 forelectrically .joining inner c ondnctors of cable en d connectors.similar tothosedof 7. In this modication the longitudinal slits da Fig.7 are. omitted, the conductor ends having tubular or hollow ends l t5;providing .opposed sockets |22.V The plug is in thefcrin of a hollowinetal tube having', a billbous nr ,enlarg'd central portion Hcorresponding to the lozengefshaned central portionof the'plug lllpreviously deserihed in connectionfvqithfilig. y7.

Longitudinally vr Extending slots v| ,i 7 are tanned in the tubular plugand op'en alternately through Cil Elio foroooiiom @nos ilio'ofso ...thatthe Plug io portions ||`8 1onth e inside cfy the conductor tube endslllvThee n(larged central lozenge portion of the ,connectoplug has vtaperedor conicahsurfaesHB which correspond to the ta- ;neredsides 6,1,ofwtheplngjm One method of YI "Kllllfllllgithe comnresslible nlug ||5is to turn it vtoslinaeonglathe froxri hrass, bronze, or bel'rllium,.Cooper S looft@ Whiohaxiol-boro |20 sllrlled and thevslotslll'l.areinade by saw cuts from opposite. sodo! `One oflthe cylindricalYportions |2| on the .ends of the 4plug isfored intofhe 4end, socket |22l ofpiie ,of the 'nnerf terminal conductorsV 62 prior tosassinbly 'fthecoaxial lines being joined. 'Tho diameter. o .,.aoh-.of thooylidrioal ond nortions |2| of the plug is greaterthan the internalydiameter,:c ifjeasch ofthesocketsv I 22` so that the I2-.mais receivedinthe sockets twith .a snap ,or VVfrictioniit w 'ch holds. the partstogether until ng Device, disclosing present invention, theluplication;for ,which ,was c opending .with the @soient-oosoiRotor@nooiifsoloo modo to ooaeeflieg, oopliooiioo .for vUnitedStates Patent Seri?! N-O ,214???31 ,lie-d; Mch 19511 for, Cdn* nootor.for .Elootrolol Tionsmissioo Liooo! do- 'bing .and.laimngisubiectmatterrelated to that liao @roseo ooooi '-111 aooorlorioo with the .PotentStatutes .the principles ,ofthe present :invention may be utilized to,olio von, numeroso .mom-@ations and alterati ,rio ooioa'oootomrlaiod,substitution arts 4and hanges .in construction being of` p looortao toas@oogst it boing understood that negano ato-,aon inne' drawings .anddeare given merely f orpurposes of scr explanation and illustrationwithout intending tplirnitthe isconewohtheclaiuis to the `specific dei"What'.iflainu.anllcsireto .secure lbyliettersPotion@ilieoaitedfsaiesfisf l-jlnfao 'a1l 1' n, coiipling structure orthe like, tubnlar-yconductors disposable endto endrelatidmsleeves.,embracingtheconductors, means fves andperrnitting rel:.tive

iiriterlcicllmig the rothesleevesdand .conductors having" io'f'o .time,soroivihoods iol" retaining the .sleeves onthecndutorsand.for drawingthe tors together saidscrew threads permitl g axially beyond the rijyingsaid one sleeve, ined with a 7substantially guneter y tliantne footldiameter of the lthreads ontheconductor .carryngsaid one sleeve, andmeans onthe pther. ,condi1ctor providing a substantiolls/cylmdricaloutwardly directed face of less diameter than .theroot diameter of thethreads on such other conductor, said out vard ooo boingroooitaolo.iolosoooioally within the guidering t9 1I Jilot thcconduotors intovaligned olation 'f-S .they l ltown together 2. In a co-af alline Quphngstructure or the litre, vtubular f. rs nisnosable in yend Lto end r I 1,'slee,ves, inbracing the conductors, .orlookiog ilioslsoros andpermitting relative rotation thereof, the sleeves andtconductors havingintertting formations for retaining the sleeves on the conductors andfor drawing the conductors together, said formations permitting facileremoval of the sleeves from the conductors, a circular guide ringcarried by one of the sleeves as a part thereof and projecting axiallybeyond the end of the conductor carrying said one sleeve, said guidering being formed with a substantially cylindrical inwardly directedface, and means on the ends of the conductors providing substantiallycylindrical outwardly directed guide surfaces receivable telescopicallywithin the cylindrical face of the guide ring, said guide surfaces andthe inwardly directed face of the ring being of less diameter than theminimum diameter ofl all Vother parts of said one sleeve and the guidesurfaces being slidable against the guide ring face to pilot theconductors into aligned relation as the latter are drawn together.

3. In a `co-axial line coupling structure or the like, tubularconductors disposable in end to end relation, sleeves embracing theconductors, means interlocking the sleeves and permitting relativerotation thereof, the sleeves and conductors having interflttingformations for retaining the sleeves on the conductors and for drawingthe conductors together, said formations permitting facile removal ofthe sleeves from the conductors, a circular guide Vring carried by oneof the sleeves as a part thereof and projecting axially beyond the endof the conductor carrying said one sleeve, said guide ring being formedwith a substantially cylindrical inwardly directed face, and an axiallydirected substantially cylindrical shell flange on the other conductorreceivable telescopically within the guide ring and having an outwardlydirected substantially circular face in sliding relation to the inwardface on the guide ring, to pilot the conductors into aligned relation asthe latter are drawn together, said shell flange face and said guidering face being of less diameter than all other parts of the sleeves.

4. In a co-axial line coupling structure or the like, tubular conductorsdisposable in end to end relation, sleeves embracing the conductors,means interlocking the sleeves and permitting relative rotation thereof,the sleeves and conductors having interfitting formations for retainingthe sleeves on the conductors and for drawing the conductors together,said formations permitting facile removal of the sleeves from theconductors, a cir-cular guide ring carried by one of the sleeves as apart thereof and projecting axially beyond the end of the conductorcarrying said one sleeve, said guide ring being formed with asubstantially cylindrical inwardly directed face, and axially directedsubstantially cylindrical relatively thin shell flanges on the ends ofthe conductors, said shell flanges having substantially cylindricaloutwardly directed guide surfaces receivable telescopically Within theguide ring, the shell flanges being circumferentially embraced by theguide ring and slidable relative to and axially of the guide ring faceto pilot the conductors into aligned relation as the latter are drawntogether.

5. In a co-axial line coupling structure or the like, tubular conductorsdisposable in end to end relation, sleeves embracing the conductors,means interlocking the sleeves and permitting relative rotation thereof,the sleeves and conductors having interiitting formations for retainingthe sleeves on the conductors and for drawing the conductors together,said formations permitting facile removal of the sleeves from theconductors, a circular guide ring carried by one of the sleeves as apart thereof and projecting axially beyond the end of the conductorcarrying said one sleeve, said guide ring being formed with asubstantially cylindrical inwardly directed face, and axially directedsubstantially cylindrical relatively thin shell flanges on the ends ofthe conductors, said shell flanges having substantially cylindricaloutwardly directed guide surfaces receivable telescopically within theguide ring, the shell flanges being circumferentially embraced by theguide ring and slidable relative to and axially of the guide ring faceto pilot the conductors into aligned relation as the latter are drawntogether, the shell ange guide surfaces and the face of the guide ringbeing of less diameter than the minimum diameter of all other parts ofthe sleeves, and said shell flanges having lconfronting radially narrowand substantially circular end faces receivable abuttingly against oneanother upon said drawing together of the conductors.

6. In a co-axial line coupling structure or the like, tubular conductorsdisposable in end to end relation, sleeves embracing the conductors,means interlocking the sleeves and permitting relative rotation thereof,the sleeves and conductors having interfltting formations for retainingthe sleeves on the conductors and for drawing the conductors together,said formations permitting facile removal of the sleeves from theconductors, a splice tube disposed between the ends of the conductors inaxially aligned abutting relation to the conductors and wholly withinthe axial limits of the sleeves, and pilot means having substantiallycylindrical interiitting surfaces at the adjacent ends of the splicetube and the conductors for guiding the parts together during assemblyand for holding the splice tube in predetermined co-axial relation toeach of the conductors, said pilot means including a circumferentiallyextending radially inwardly directed flange on the inside of one of thesleeves, said flange being in engagement with the splice tube and alsowith one of the conductors and being disposed substantially in the planeof abutment of the splice tube and said one conductor.

7. In a line coupling structure, a pair of substantially rigid tubularconductors disposable in end to end relation, a pair of sleevesembracing the conductors, the sleeves and conductors having interttingformations for retaining the sleeves on the conductors and for drawingthe conductors together, said formations permitting facile removal ofthe sleeves from the conductors, means interlocking the sleeves andpermitting relative rotation thereof and of the conductors retainedthereby, one of the conductors being formed with a circumferentiallyextending external radial shoulder spa-ced axially from the conductorend, and a radially inwardly directed circumferential flange on one ofthe sleeves, said flange projecting axially beyond the end of theconductor embraced by the sleeve having such flange and being engageablewith said shoulder to locate the sleeve on the conductor, the ends ofthe drawn together conductors abutting one another in a plane spacedaxially of the structure from the engaged shoulder and ange.

8. In a line coupling structure, a pair of substantially rigid tubularconductors disposable in end to end relation, sleeves embracing theconductors, the sleeves and conductors having in- 17 terttine formationsfor retaining the sleeves on the conductors and for drawing theconductors together, said formations permitting facile removal o thesleeves from the conductors, means interlocking the sleeves andpermitting relative rotation thereof and of the conductors retainedthereby, a radially disposed circumferential shoulder formed on andadjacent an end of one of the conductors, means on one of the sleevesprojecting both axially beyond such end of the one conductor andradially inward and formed with a radial shoulder in confrontingrelation to the shoulder on the conductor, the sleeve shoulder beingengageable against the conductor shoulder to locate the sleeve on theone conductor, and

means on the other conductor receivable within the shouldered locatingmeans engageable against the end of the one conductor, whereby thelocating means acts io engage the other conu ductor as the conductorsare drawnV together to pilot the conductors into axial alignment.

9. In a line coupling structure, a pair of substantially rigid tubularconductors disposable in end to end relation and having externallythreaded end portions, internally threaded sleeves embracing thethreaded portions of the conductors, means interlocking the sleeves andpermitting relative rotation thereof in screwing the sleeves onto theconductor ends to draw the latter together into said relation, means onone of the sleeves and engageable with the extreme ends of bothconductors simultanously .tor piloting the conductors together inaligned axial relation, and one oi the sleeves and one of the conductorsbeing formed with radial shoulders engageable with one another forlocating the shouldered parts in predetermined axial relation when theyare screwed together, the shoulder on the conductor being spaced axiallyfrom the end of the latter whereby the drawn together conductors abutone another in a plane spaced axially of the structure from the engagedshoulders.

l0. In a line coupling structure, a pair of substantially rigid tubularconductors disposable in end to end relation and having externallythreaded end portions, internally threaded sleeves embracing thethreaded portions of the conductors, means interlocking the sleeves andpermitting relative rotation thereof in screwing the sleeves onto theconductor ends to draw the latter together into said relation, pilotmeans on one of the sleeves and projecting beyond the end of theconductor having such sleeve screwed theren on, said pilot means beingformed to embrace the other conductor as the conductors are drawn t0-gether to guide the conductors into axial alignment, and one of thesleeves and one of the conductors being formed with radial shouldersengageable with one another for locating the shouldered parts inpredetermined axial relation when f they are screwed together, theshoulder on the conductor being spaced axially from the end of thelatter whereby the drawn together conductors abut one another in a planespaced axially of the structure from the engaged shoulders.

11. In a line coupling structure, a pair of substantially rigid tubularconductors oi circular secu tion disposable in end to end contactingrelation, sleeves embracing the conductors, the sleeves and conductorshaving interiitting formations for re taining the sleeves on theconductors and for drawing the conductors together, said formationspermitting facile removal of the sleeves from the conductors, meansinterlocking the sleeves and permitting relative rotation thereof and ofthe lar conductors one of which has on one end a circumferentialdirected shell of relatively thin section, the conductors being ofcircular section, the shell having an internal diameter substantiallythe same as and an external diameter less than the correspondingdiameters of the respective conductors, a pair of sleeves interlockedagainst axial separation and rotatable one relative to the other, eachsleeve embracing one of the conductors, interrltting means on theconductors and sleeves permitting facile removal of the sleeves from theconductors for drawing the conductors together axially and holding themin end to end relation with the conductor end shell abutting the end ofthe other conductor, and pilot means carried by one of the sleeves forguiding the conductors into axial alignment as they are drawn together,pilot means being substantially circular and having an internal diameterless than the external diameter of either of the conductors andembracing the end shell to reinforce the latter.

13. In a line coupling structure, a pair of substantially identicaltubular conductors having on their ends relatively thin circular shellsextending the internal conductive surfaces of the conductors, theconductors being of circular section, the shells having an internaldiameter substantially the same and an external diameter less than thecorresponding diameter of the respective conductors, a pair or" sleevesinterlocled against axial separation and rotatable one relative to theother, each sleeve embracing one of the conductors, intertting means onthe conductors and sleeves permitting facile removal or the sleeves fromthe conductors for drawing the conductors together axially and holdingthem in end to end relation with the circular shells in edgewiseabutment providing substantially continuous internal conductive surfacesof substantially constant diameter through the structure, and pilotmeans carried by one of the sleeves and embracing the end shells toreinforce the latter and to guide the conductors into axial alignment asthey are drawn together, said pilot means being substantially circularand having an internal diameter less thanv the external diameter of theconductors.

14. In a coaxial line coupling structure having outer tubular conductorsand means for drawing the conductors together axially and progressivelyand for holding the same in end to end axially fixed assembled relation,an inner conductor element ooaxially disposed in each outer conductor,insulating means connecting the inner conductor elements to therespective outer conductors and constraining the inner conductorelements to axial movement with the outer conductors, the elementshaving axially aligned spaced confronting ends, and a connector elementdisposed between the ends of the inner conductor elements, the innerconductor elements and the connector element being of circular crosssection and having substantially the saine maximum diameter,

Ythe ends of the conductor elements and the connector element beingarr-an; d in interiitting relation in the provision or" plug and socketconnectionsbetween the inner conductor elements and vthe connectorelement at each end of the latter,

the innerrpiug end ol connection having an external tapered surface andthe outer Vat least one of the elements haring a resilient and radiallyyieldalole end for expansion and contraction thereof in permittingslight axial movement voi one element relative to another whilemaintaining the line contact electrical connections,- the outer surfaceof the connector element at said maximum constituting the electricalconductive suriace between the axially spaced ends of the innerconductors.

l5. ln combination in a coaxial line structure, aY pair ol rigid tubularconductors disposable in end to end axially relation and having substantially smooth internal surfaces, coupling means for drawing theconductors into and holding the conductors in s a pair or inner circularsectioned. al diameter conductor elements disposed w hin the tubularconductors and axially aligned with one another, the inner conductorelements having confronting axially spaced ends when the tubularconductors are so held, insulators of solid dielectric materialsubstantially completely filling the annular spaces between the tubularconductors and the respective inner conductor elements and serving tosupport the latter in the tubular conductors, a con-= nector elementdisposed between the inner conductor element ends, the ends of theconductor elements and the connector element being arranged inintertting relation in the provision of Vplug and socket connectionsbetween the inner conductor elements and the connector element at eachend of the latter, the inner plug end of each such connection having anexternal tapered surface and the outer socket end. of each suchconnection making substantially circular line contact with the taperedsurface of the inner plug intertting therewith to establish electricalcontacts between the elements, at least one of the elements having aresilient and radially yieldable end for expansion and contractionthereof in permitting slight axial movement of one element relative toanother while maintaining line contact electrical connection, and theouter surface of the connector element including a portion ofsubstantially the same diameter as the inner conductor elements andconstituting the electrical conducting surface between the innerconductor elements, the solid insulator supporting each inner conductorextending axially along such supported condoctor substantialy to theplane of the circular line Contact between such conductor and theconnector element.

i6. In a coaxial line coupling structure having outer tubular conductorsand means for drawing the conductors together axially and holding thesame in end to end axially fixed assembled relation, inner conductorelements coaxially disposed one in each outer conductor, and a connectorelement disposed between the ends i the inner conductor elements, theends of the elements being formed with connections which include'tapered surfaces in the provision of intertting self-centering portionsin the connections between the connector element and the innerconsubstantially ductor elements, the inner conductor elements and theconnector element all being or circular cross section and havingsubstantially the same maximum diameter, and the connections includinganother intertting connection portion between the connector element andat least one of the inner conductor elements for holding the connectorelement in assembled relation to the one inner conductor element duringassembly and disassembly of the coupling Structure, said otherconnection portion compri ing a plug and socket combination in which anaxially extending plug on one element is received in and irictionallyrestrained against withdrawal from a socket in another of the elements.

17. In combination in a coaxial line structure, a pair of rigid tubularconductors disposable in end to end axially fixed relation and havingsub stantially smooth internal surfaces and threaded external surfaceportions adjacent their ends, means providing a radially disposedcircumferential shoulder on at least one of the conductors, a pair ofinner conductor elements disposed within the tubular conductors andaxially aligned with one another, the inner elements having ends inspaced confronting relation, a conductive element disposed between theconfronting ends of the inner conductor elements, the ends oi theconductor elements and the connector element being arranged ininterrltting relation in the provision of plug and socket ccnnectionsbetween the inner conductor elements and the connector element at eachend oi latter, the inner plug end of each such connection having anexternal tapered surface and the outer socket en-d of each suchconnection making circular line contact with the tapered surface of theinner plug interiitting therewith to establish electrical contactsbetween the elements, at least one of the elements having a resilientand radially yieldable end for expansion and contraction thereof inpermitting slight axial movement of one element relative to anotherwhile maintaining the line contact electrical connection, a iirstinternally threaded sleeve embracing the threaded portion of one of thetubular conductors, a secon-d internally threaded sleeve embracing thethreaded portion of the other tubular conductor, radial ange means onone of the sleeves engageable with the radial shoulder on said oneconductor in axial bearing relation to locate the one sleeve in screwning the same onto the one conductor, and means interlocking theinternally threaded sleeves to permit relative rotation thereorn in scewing the sleeves on the respective tubular conductors to draw thelatter together axially and to hold the conductors assembled in saidaxially xed relation.

18. In combination in a coaxial line structure, a pair of substantiallyrigid tubular conductors disposable in end to end axially fixed relationand having Substantially smooth internal surfaces, a pair of centralconductor elements disposed coaxially within the tubular conductors andaligned with one another, the confronting ends of the central conductorelements being axially spaced from one another and formed withsubstantially identical tapered surface portions, a conductive elementdisposed between the central conductor element ends and havingsubstantially identical tapered surface portions on its ends forintertting with the central conductor element tapered end portions forpermissive reversal of the conductive element in assembly,

21 the angle of the tapered portions on thev oonductor element endsdiffering from the angle of the tapered portions on the conductiveelement ends to provide substantially circular line contacts between theconductor elements and the conductive element, one of the elements beingradially yieldable to permit expansion and contraction thereof uponrelative axial movement of the yieldable element and another of theelements contacting such yieldable element to maintain said line contacttherebetween in the form of a exible connection, the line contact movingalong the tapered1 surface of the inner of the intertted elements duringsaid relative axial movement,y and means engageable with externalportions of the tubular conductors for drawing the latter together andholding them assembled said axially fixe-d relation, whereby axialshifting of one of the central conductor elements relative to theaxially vfixed tubular conductors is accommodated in the iiexibleconnection.

19. In combination in a cc-axial line structure, pair of substantiallyrigid tubular outer conductors disposable in endv to end axially fixedrelation and having substantially smooth internal surfaces, a pair ofinner conductor elements disposed co-axially within the tubularconductors and aligned with one another, solid dielectric materialsubstantially completely nlling the annular spaces between the tubularouter conductors and the respective inner conductor elements and servingto support the latter in the tubular conductors, the confronting ends ofthe inner conductor elements being axially spaced from one another andformed with substantially identical tapered surface portions, aconductive element disposed between the inner conductor element ends andhaving substantially identical tapered surface portions on its ends forinteritting with the conductor element tapered end portions forpermissive reversal of the conductive element in assembly, the angle ofthe tapered portions on the conductor element ends differing from theangle of the tapered portions on the conductive element ends to providesubstantially line contact between the conductor elements and theconductive element, the solid dielectric material supporting each innerconductor extending axially along such supported conductor substantiallyto the plane of the circular line contact between such conductor and theconnector element, one of the elements being radially yieldable topermit expansion and contraction thereof upon relative axial movement ofthe yieldable element and another of the elements contacting suchyieldable element to maintain said line contact therebetween in the formof a flexible connection, the line contact moving along the taperedsurface of the inner of the intertted elements during said relativeaxial movement, and means engageable with external portions of thetubular conductors for drawing the latter together and holding themassembled in said axially fixed relation, whereby axial shifting of oneof the ccnductor elements relative to the axially xed tubular conductorsis accommodated in the ilexible connection.

20. In combination in a co-axial electrical line structure, tubularouter conductors in end to end axially fixed relation, center conductorelements disposed in end to end relation, means supporting the centerconductor elements within the tubular outer conductors in co-axialrelation, the ends of the center conductor elements being of tubularform, opening toward one another and having confronting substantiallycircular substantially knife edges, and a connector element between theends of the center conductor elements, said connector having tapered endportions located within the tubular ends of the conductor elements ininterfitting relation, each knife edge making substantially circularline Contact with the connector element on one of the tapered endportions, one of the elements being radially yieldable to pei-.Witexpansion and contraction thereof upon rel v axial rnovenient of theyieldable element and another of the elements contacting such yieldableelement to maintain said line contact therebetween in the form of aflexible connection, the line contact moving along the tapered surfaceof the inner of the interiitted elements during 'l relative axialmovement whereby sli-. nig of one of the conductor eleine relative tothe axially fixed tubular conductors is accommodated in the flexibleconnection.

21. In combination in a co-azrial electrical line structure, tubularouter cor rs in end to end axially fixed relation, cente conductorelements disposed in end to end lati n, means supporting the centerconductor elements within the tubular outer conductors in .co-axialrelation, the ends of the sente ments being in the form of re" axialslots opening' through the provision of ra tubes having confrontingsubst substantially knife edges comprising said fingers, and a connectorelement between the ends of the center conductor elements, saidconnector having tapered end portions located within the tubular ends ofthe conductor elements, the finger ends comprising each knife edgemaking substantially circular line contact with the connector element onone of he tapered end portions, the resilient tubes being adapted toexpand and contract as the center conductor elements are moved axiallytoward and away from one another in assemblyand adjustment the provisionof a flexible connection maintaining said circular line contacts at theknife edges, whereby axial shifting of one of the conductor elementsrelative to the axially fixed tubular conductors is accommodated in theflexible connection.

22. In a line coupling structure, a pair of substantialli7 rigid tubularconductors, sleeves ernbracing the conductors, the sleeves andconductors having intertting for tions for drawing the conductors intothe sleeves upon relative rotation, a splice tube disposed between theends of the conductors wholly within the axial lin/lits of the sleeves,pilot .means having a cylindrical surfaces at and embracing the splicetube ends and the ends of the conductors for guiding the parts togetherduring assembly for holding the splice tube in predetermined oo-axiallation to each of the conductors, means resisting axial separation ofthe sleeves, said drawing of the conductors into the sleeves acting tocornpress the splice tube axially between the ends of the conductors,inner conductors extending axially through the outer conductors, bodiesof solid insulating material embracing the inner conductors andsupporting the saine in their respective outer conductors, a conductiveconnector element extending between the inner conductors, and anotherbody of solid insulating nnterial einbracing the connector element andsupporting the latter within the splice tube.

ular

23. In a co-axial line coupling structure an end fitting for a linecable having an inside conductor surrounded by and insulated from abraided tubular conductor, the end tting comprising an inner conductorfor connection to one end of the inside conductor of the cable, an outerrigid conduotor of tubular form and circular cross section internally,an insulating body separating the fitting conductors and supporting theinner one 1o-axially within the outer conductor, one end of the outerconductor of the tting being formed to receive coupling means inassembling the end fitting in the coupling structure, the other end ofthe outer conductor of the fitting being formed with an internalcylindrical chamber and. a

`radially disposed circular shouldeiya clamping sleeve having one endfor receiving and embracing the cable and another end receivableteleseopically over said other end oi the outer oon- -ductor, the sleevehaving a substantially radialcircular opening at the sleeve shoulder ofless '24 diameter than the cylindrical chamber and shoulder of theconductor so that the sleeve shoulder projects radially inwardly fromthe cylindrical Walls of the chamber in said other end. oi the outerconductor in the provision of a diameter increase in the plane of thetransition.

JAMES` R. BIRD.

References Cited in the le of this patent UNITED STATES PATENTS NumberName Date 514,734 Shields Feb. 13, 1894 699,455 Cronk May 5, 1902739,707 Park Sept. 22,1903

1,841,473 Green Jan. 19, 1932 1,871,839 Carter Aug. 15, 1932 1,932,448Clavier Oct. 31,1933

2,153,527 Battermann Apr. 4, 1939 2,294,738 Bruno Sept. 1, 19422,305,668 Bruno Dee. 22, 1942 2,332,529 Reppert Oct. 26, 1943 2,404,797Hansen July 30, 1946 2,425,834 Salisbury Aug. 19, 1947 2,425,959Schoenborn Aug. 19, 1947 2,443,921 Moe June 22, 1948 2,453,759 RobinsonNov. 16, 1948 2,497,922 Batt Feb. 21, 1959 FOREIGN PATENTS NumberCountry Date 50,021 Netherlands Oct. 15, 1940 485,409 France Oct. 12,1917

